httpd-modules-dev mailing list archives

strange behaviour using mod_proxy when the r->filename partially overlaps the requested uri

Date

Tue, 21 Aug 2012 11:39:27 GMT

Dear all
i've got a strange behaviour in my custom module:
it seems that if the set filename overlaps the requested uri ths final
uri passed to mod_proxy is wrong, or has some added strange
characters.
some information:
* the module is activated only when the requested uri contains the
string "/files/anteprima"
* the module just redirect the request to mod_proxy changing the
request from "/files/anteprima" to "nocachedfiles/anteprima/"
* i know all is hardcoded here but is just to reproduce the problem
My module is configured in a vhost and related to a specific Location:
<Location /data>
SetHandler kcache
</Location>
if i make a request to this module, for example:
http://kcache.foo.com:19007/data/_www.foo.com/files/anteprima/whatyouwant
Looking at the code it should be redirected to:
proxy:http://www.foooo.com/nocachedfiles/anteprima/12345
but looking at apache logs i see:
[Tue Aug 21 13:27:01 2012] [debug] mod_proxy_http.c(56): proxy: HTTP:
canonicalising URL //www.foooo.com/nocachedfiles/anteprima/12345
dJ\x98\x01\x7f
[Tue Aug 21 13:27:01 2012] [debug] proxy_util.c(1515): [client
127.0.0.1] proxy: *: found forward proxy worker for
http://www.foooo.com/nocachedfiles/anteprima/12345 dJ\x98\x01\x7f
[Tue Aug 21 13:27:01 2012] [debug] mod_proxy_http.c(1973): proxy:
HTTP: serving URL http://www.foooo.com/nocachedfiles/anteprima/12345
dJ\x98\x01\x7f
[Tue Aug 21 13:27:01 2012] [debug] proxy_util.c(2067): proxy:
connecting http://www.foooo.com/nocachedfiles/anteprima/12345
dJ\x98\x01\x7f to www.foooo.com:80
You can see some "garbage" at the end of the string.
I've tried to investigate a lot on in, but i'm not able to figure it
out... notice that if you change the length of the newurl string, or
if you change it from:
"proxy:http://www.foooo.com/nocachedfiles/anteprima/12345";
to
"proxy:http://www.foooo.com/nocachedfiles2/anteprima/12345";
The module tries correctly to load
http://www.foooo.com/nocachedfiles2/anteprima/12345 withoud any
garbage at the end.
It seems to be a combination of overlaps of the requested uri, the
destination file and their length... here there is the exact code to
reproduce it:
One last thing :
is not yet clear to me if is correct to put this kind of redirection
in ap_hook_translate_name or if i have to use another type of hook,
by the way if you use a ap_hook_handler in the same conditions you get
an http contatenated at the end of your filename:
[Tue Aug 21 13:37:02 2012] [debug] proxy_util.c(1515): [client
127.0.0.1] proxy: *: found forward proxy worker for
http://www.foooo.com/nocachedfiles/anteprima/12345http
Any idea?
Thanks to all in advance
/************************************************/
#include <httpd.h>
#include <http_protocol.h>
#include <http_config.h>
static void register_hooks(apr_pool_t *pool);
module AP_MODULE_DECLARE_DATA kcache_module = {
STANDARD20_MODULE_STUFF,
NULL,
NULL,
NULL,
NULL,
NULL,
register_hooks
};
static int kcache_handler_translate(request_rec* r)
{
if (r->method_number != M_GET && r->method_number != M_POST){
return HTTP_METHOD_NOT_ALLOWED;
}
if(
strstr(r->unparsed_uri, "/files/anteprima")==NULL){
return DECLINED;
}
char *newurl = "proxy:http://www.foooo.com/nocachedfiles/anteprima/12345";
r->filename = apr_pcalloc(r->pool,strlen(newurl));
strcpy(r->filename,newurl);
r->proxyreq = PROXYREQ_PROXY;
r->handler = "proxy-server";
return DECLINED;
}
static void register_hooks(apr_pool_t* pool)
{
static const char *succ[] =
{"mod_proxy.c","mod_alias.c","mod_userdir.c", NULL};
ap_hook_translate_name(kcache_handler_translate, NULL, succ,
APR_HOOK_MIDDLE);
}
/***********************************************/
--
/*************/
nik600
http://www.kumbe.it